This chapter covers the development of a virtual simulation platform for training a semiautonomous robotic vehicle (SARV) operator via an open-source game engine called Unity3D. The SARV such as remotely operated vehicles (ROVs) is becoming increasingly popular in the maritime industry for risky jobs in inhospitable environments. The primary element in carrying out underwater missions in a hostile environment lies within the skills and experience of an ROV pilot. Training for ROV pilots is essential to prevent damage to expensive field equipment during the real operations. The proposed simulator differs from the existing simulators in the market is the use of modern game engine software to develop a "serious game" for ROV pilot trainee at much lower cost and shorter time-tomarket. The results revealed that proposed virtual simulator can develop a high-fidelity virtual reality training for the underwater operation guided by classification society.